One-way clutch comprising wedging means

ABSTRACT

The invention relates to an overrunning clutch with extremely high response characteristics and very little backlash. Essentially, careful consideration of excentricity in wedges associated between a driving member and a driven member in combination with friction factor between the driving, driven, and wedge or cam surfaces achieves a highly efficient clutch. Preferably, a primary wedge or cam is associated with the secondary wedge or cam, with both cams urged into an actuating position causing a driving relationship between the driven member and the driving member. This driving relationship is overcome upon a reverse movement of the driving member or an overriding of the driven member, all occasioned because of the excentric characteristics defining the wedges or cams in association with excentric surfaces on the driven member cooperating with radial steps of lips so that the cams always rotate or remain in the same relative relationship to the driven member.

United States Patent [72] Inventor JeanF.G.M.L.Charpentier254NHigltland,Altron,0hio44303 [21] Appl.N o. 836,862 [22] Filed June26,1969 [45] Patented July 27,1971

[54] ONE-WAY CLUTCH COMPRISING WEDGING MEANS 19Claims,5DrawingFigs.

[52] U.S.CI. 192/45.1, 192/74, 188/828 [51] lnt.Cl. ..F16d41/07. [50]FleldofSearch 192/45.1, 74;188/82.8

[56] ReferenoesCited UNITED STATES PATENTS 1,946,048 2/1934 Verderberl92/45.1UX 684,478 10/1901 Trimble..... 192/45.1 2,785,782 3/1957Dodge... 192/45.1X 3,235,046 2/1966 Fulton... l92/45.l 3,236,345 2/1966Dietz 192/45.1

Primary Examiner-Allan D. Hermann Attorney-Oldham and Oldham ABSTRACT:The invention relates to an overrunning clutch with extremely highresponse characteristics and very little backlash. Essentially, carefulconsideration of excentricity in wedges associated between a drivingmember and a driven member in combination with friction factor betweenthe driving, driven, and wedge or cam surfaces achieves a highlyefficient clutch. Preferably, a primary wedge or cam is associated withthe secondary wedge or cam, with both cams urged into an actuatingposition causing a driving relationship between the driven member andthe driving member. This driving relationship is overcome upon a reversemovement of the driving member or an overriding of the driven member,all occasioned because of the excentric characteristics defining thewedges or cams in association with excentric surfaces on the drivenmember cooperating with radial steps of lips so that the cams alwaysrotate or remain in the same relative relationship to the driven member.

PATENTED JUL27|971 3,595,354

sum 1 OF 3 LDCUS OF CR 0PT. OF

THE UPPER CAMS INVENTOR JEAN FG. M. L. CHARPENTIER ATTORNEYS PA'TENTEUJUL27 I971 4.5 y/vprons a .45 YMPTO 7-5 5 SHEET 2 BF 3 INVENTOR. JEANFTG.I"I.L.CHARPENTIER PATENTEllJuLzmn SHEET 3 of 3 3,595,354

locus OF iii/L 0P7 INVENTOR. JEAN FG.I"I.L. CHARPENTIER BY w. v(OWcMcu/L. f"

(lease (In M -w ATTYQ,

ONE-WAY CLUTCH COMPRISING WEDGING MEANS This invention relates to anoverrunning clutch concept in which the device locking together thedriving and driven races are designed to allow them the followingcharacteristics:

A. The total area of each series of the corresponding surfaces that thelocking devices apply permanently on each one of the races has amagnitude of the same order as the total area of the active surface ofthe race on which it is applied.

B. The forces that the locking devices induce on the active surfaces ofthe races, when the driven race resists the motive action of the drivingrace, generate a uniform pressure distribution on the races activesurfaces, and therefore a uniform distribution of the induced tangentialdriving force.

The purpose of such specific characteristics is to provide a clutch, thecomponents of which keep pennanently the same initial configurationindependently from the operational constraints they are subjected inrespect to the induced forces and the angular velocity.

The operational constraints are applied under the following conditions:

A. The pressure developed between the active surfaces of the races andthe corresponding surfaces of the locking devices, has a magnitude ofthe same order as that of the journal of a shaft on its bearing, andtherefore prevents the components from local elastic, and a fortioripermanent deformation.

. B. The uniformity of the pressure prevents the components from anychange of configuration.

C. The locking devices operate without detectable motion relative to thedriven race on which they are mounted and therefore compelled to rotateat the same angular velocity.

D. As no deformation and no relative motion can occur, the efficiency ofthe clutch is permanently equal to the theoretical value, and the lowand uniform pressure set to work prevents the components from wearallowing them an indefinite life time.

E. Even if some wear could occur, it would never change the theoreticaloperating conditions because it would be uniform like the pressuredistribution, so that the shape and the adaptation of the componentsunder contact would remain homothetic to their initial configuration.

F. From condition E, no high accuracy is required from the machine work.

G. No high hard treatment is required for the metal utilized.

H. No considerable thickness for resisting the constraints deformationis required from the outer race, because the pressure applied on isuniformly distributed.

For a better understanding of the invention reference should be had tothe accompanying drawings wherein:

FIG. 1 is a transversal view, partially broken of an overrunning clutchwith an external drive race;

FIG. 2 illustrates the fundamental shape and the geometry of the lockingdevices, and the way to determine the optimum magnitude of theirparameters to satisfy the conditions defined above;

FIG. 3 represents the functions variation of the two main parameters,

FIG. 4 is a transversal view of an overrunning clutch with an internaldriving race, and

FIG. 5 illustrates the application of the overrunning clutch principleto the nonautomatically controlled clutches and brakes.

To get the characteristics described above, an overrunning clutchcorresponding to the invention is comprised of the components describedas follows, and illustrated in FIGS. 1, 2, 4 and 5, while the parametersand the functions of two of them are illustrated in FIGS. 2 and 3.

In FIG. 1, the numeral indicates a driving race, or motor race,comprising an internal cylindrical active, or motive or driving surface11 with a circumferential profile, mounted externally with respect tothe other clutchs components, for performing some rotary, continuous oroscillating motion, around a central longitudinal axis XX of trace 0 inthe Figure.

A driven race 20 or receptor, coaxial with the driving race 10 andintegral with or fixed by means of a key 31 on the driven shaft 30. Thedriven race 20 looks like a conventional Ratchet Wheel but with largerteeth which form a series of excentric partial cylindrical surfaces 21with a circumferential arc profile, which constitute a series of spirals21, all developing their opening in the same positive rotationaldirection. The surfaces 21 are convex because the driving surface 11 isexternal to the connecting mechanism. They are positioned facing thedriving surface 11 of the motor race 10 at such a distance apart toconstitute a series of partial excentric cylindrical primary annularspaces.

Each one of the surfaces 21 constitutes the bearing of a cam, their endis separated from the origin of the next by the radial step 22 which isprolonged by the lip 23 formed at the end of every bearing surface 21and radially directed toward the driving surface 11.

Between the driving and driven races, a series of primary earns 40 aremounted which look like long curved wedges with each one of them havingits base surface 41 permanently seated in coincidence on one of thebearing surfaces 21, or partial excentric surfaces of the driven race20, and compelled therefore to rotate with it. The sum of the base areas41 of the primary earns 40 has the same order of magnitude as the totalarea of the driven races bearing surface on which they are seated.

The excentricity E of the bearings profile 21, which is identical forthat of the primary cams base profile E is measured by the ratio of thedistance e, extended between the general center of rotation O of thedriving race 10 and the center of curvature,CR (optimum), of saidbearings profile 21, to the radius R of the motor races driving surface11, or

E =Ep This ratio measures the tangent of the Angle e of Disengagementgsuch that =tan 61 The numencal value of tan 5,, is greater than that ofthe friction coefficient, f, of the friction developed between thebearing surfaces 21 and the base surfaces 41 of the primary cams 40. Theexcentricity of the bearings profile 21 and primary cams 40 base profile21, satisfies the condition EB E, =fi=tan e f.

A guide 43 is formed at the fronteEofthe primary cams 40 which engagesin a split 24 formed in the lip 23 of the hearing 20. The head surfaces42 of the primary earns 40, facing at a distance apart the activesurface 11 of the motor race 10, constitute a new series of partialexcentric secondary annular spaces, while their circumferential profilesconstitutes a new series of secondary spirals, all developing theiropening in the same positive rotationaldirection. The excentricity Ep ofthe primary cams 40 head profile 42 is measured by the ratio of thedistance e, extended between the main center 0 and the center ofcurvature CR OPT of the primary cams head profile 42 to the radius R ofthe motor race profile 11, or Ep,

- e faces to satisfy the condition E tan 6}; f.

I This ratio measures the tangent of the Ang le of En- A series ofsecondary cams 5f): each one mounted inside one of the partial excentricsecondary annular spaces, with their base surface 52 permanently seatedin coincidence on the head surface 42 of a corresponding primary cam 40.The excentricity of their base contour E is identical to that Ep of thesecond series of spirals constituted by the headprofiles 42 f tem e f.The secondary cams 50 are compelled to rotate with the primary earns 40and the driven race 20 at the same angular velocity.

The sum of the base areas of all the secondary cams has the same orderof magnitude as the sum of all the areas of the head surfaces of theprimary cams on which they are applied.

The head surfaces 52 of the secondary cams 50 are applied on the drivingsurface 11 of the motor race 10 and the sum of all their areas has thesame order of magnitude as the total of the primary earns 40, i.e. E =Eparea of the driving surface 11. On the front side of the secondary camsS is formed a guide 53 which engages in a split 24 formed on the lip 23of the bearings 20 and in a notch 54 formed on the rear face of thepreceding cam of the same series. A positive permanent tangentialforce,t, is transmitted to each cam of both primary and secondary series. Thetangential force is generated by an energizing helicoidal spring 60entirely located inside a cylindrical guide 56 machined in, and throughthe rear side 58 of the secondary cam 50.

A piston 61 with a cylindrical tail 62 is mounted in the cylindricalguide 56 to seal its orifice. The tail of the piston is mounted insidethe spring 60 to allow it an internal guide while the piston head takesupport on the front face 22 of the lip 23 of the driven race 20. Thepiston's tail does not contact the bottom of the cylindrical guide 56 sothat the positive springs tension t is entirely transmitted to the cam50. Each primary cam 40 is provided with a cylindrical guide or bore560. A coil spring 60a is provided within each of the guides 560. Apiston 610 with a cylindrical tail 62a is mounted in the cylindricalguide 56a with the tail of the piston inside the spring 60a to allow itto act as an internal guide. The head of the piston 61 abuts the frontface 22 of the lip 23 of the driven raise 20 so that the spring 60aexerts the positive tangential force 1 on the primary cam 40.

The positive tangential force 2 transmitted to the primary cams 40maintain their front side 44 applied on the rear face 25 of the lip 23in order to prevent any positive relative displacement from theirassigned initial position.

The positive tangential force 1 transmitted to the secondary cams 50maintain them engaged in contact between their bearing primary cams headsurface 42 and the internal driving surface 11 of the driving race whilenothing prevents their relative displacement.

Both the primary cams 40 and the secondary earns 50 are applied on theiradjacent surface under the pressure magnitude required to generate ontheir active surfaces the Initial Permanent Inductive TangentialConnecting Forces, or in shortening, the Priming Inductive Forces."

Through this concept, when the driven race resists the driving racemotive action, the Priming Inductive Forces always convert thetangential components of the opposed forces into the TangentialComponents of an Induced Connecting Force when the magnitude of theangle of engagement g is correctly selected. In this case, the inducedtangential driving component applied on the head 52 of the secondary cam50 by the driving surface 11, and the induced tangential resistingcomponent applied on the base 41 of its supporting primary cam 40 by thebearing surface 21 form a couple which tends to engage at once and asone cam alone, each pair of associated primary and secondary camsbetween their adjacent active surfaces. As the primary earns 40 areprevented by the lips 23 of their bearings from moving forward withrespect to the driven race 20, they behave relatively to the secondarycams 50 like an integral part of the driven race's bearing, and only thesecondary cams 50 can respond to the action of the induced tangentialconnecting force's components. Because the e excentrrcity, E =tan e ftheir base contour IS smaller than the magnitudeof the frictioncoefficient f specific of the friction developed between the contactingsurfaces the connecting forces wedge the secondary earns 50 between thedriving race 10 and the driven race 20 through the primary cams 40 thenintegral part of the driven race 20. The driven race 20 is then blockedon the driving race 10 and compelled to rotate at the same angularvelocity.

In the opposite case, when the driven race starts to rotate faster thanthe driving race in the positive direction, the tangential resistingforce initially applied on it, changes sign and tends then to disengagethe cams from wedging on their adjacent surfaces. In this positive fastrotational motion of the driven race, the primary cams are not preventedfrom any trend of backwards relative displacement. Because the magnitudeof their base profile excentricity Ep is greater than the frictioncoefficient, f, of their adjacent surfaces Ep,=e,/R

fit allows to each pair of associated primary and secondary cams, todisengage together at once as a block from the bearing surface 21 of thedriven race 20, without the smallest resistance. A good magnitude forthe angle of disengagement, 5 when both cams of each series are made inthe same material, is tan ,,=2 tan or twice the magnitude of theengagement angle 5 so that the primary earns 40 engage between thebearing surfaces 21 and the secondary earns 50 base surfaces 51 underthe same conditions as the secondary cams engage between the drivingsurface 11 and the primary cams head surface 42. The condition, tan =2tan is not limitative, but optimum.

During the phase of disengagement both primary earns 40 and secondarycams 50 are continuously applied on their corresponding active surfaces21 of the driven race 20 and driving race 10, under the inducingpressure of their energizing spring 60 in the same permanent attituderelative to said active surfaces 11 and 21, therefore permanently readyto clutch again.

The cams are protected against the action of the centrifugal force bymeans of two guides located on each side of all the cams 40 and 50, butpartially illustrated only for the cams 40, with an opening having twoparallel circumferential contours 91 and 92 of the same center as thecam base profile. A corresponding flange 94 machined on each side of thecams is able to slide in the opening taking its support from the uppersurface of the opening. The relative displacement of the cams is notprevented as the opening is extended further in the front and rear ofthe cams. The centrifugal force F C is balanced by the guides reactionwhile it generates on the cams profile a positive component I whichpushes the cam in the positive direction and operates therefore in thesame manner as the energizing springs 60. The guides are fixed on thedriven race 20 by means of rivets 93.

It has been explained and illustrated how, in this clutch the activesurfaces of all the components have their total area set to work atonce. It will be now established how the pressure is uniformlydistributed on these active areas.

In FIG. 2, is diagrammatically illustrated an overrunning clutch with asingle cam 50 interposed between the active area 11 of the motor race 10and the bearing surface 21 of the driven race 20. The center ofcurvature CR common to the surface profile 21 of the bearing and to thebase profile of the cam 50 is located on the straight line, CC drawnfrom the point C located at the middle of the length, AB, of the cam 50,and which represents the trace of the generatrix of the cams headsurface containing the center of pressure. The line CC forms the angleof engagement with the corresponding radial direction OC. The straightline CC' is the locus of all the centers of curvature corresponding toone value of the angle of engagement 5;, for the profile common to thebearing surface 21 and to the base 51 of the cam 50.

The point C corresponds to a vanishing immaterial cam reduced to thepoint C itself. Assume that center of curvature located to any position,using CR as an example. The distance CC =X is then selected as theindependent variable. When the arc of profile AB of the cam 50 tends torotate around the center CR, the point A, trace of the cams leading edgetends to leave the profile of the driving surface 11 under the negativeangle of disengagement, a, while the point B trace of the cams trailingedge, tends to penetrate the profile of the driving surface 11, underthe positive angle of attack [3.

The geometrical characteristics of the cam are as follows: The relativelength of its profile; ratio of the arc A13 to the radius R of itsdriving surface 11, l,=AB/R The relative average thickness; ratio ofone-half the sum of its ends heights, A E and IF, to the radius R of thedriving surface 11, tr=(ATZBT)/2R The mechanical parameter of the cam isi e the excentricrty of its base profile E= =tan 5, the magnitude ofwhich depends upon the nature of the cams functron.

From the geometry shown in FIG. 2, the angles of attack a and B havebeen expressed as functions of the distance X of the center ofcurvature. CR, to the point trace C, apex of the angle 5. and the anglesof the triangles of interest which are depending also of the magnitudeof the excentricity, or the angle 6. The functions are as follows:

(i-cos A)tztn 6-sin A tan a: a a

sin A tan Mfg-cos A -cos A) tan 5-sin A 10 sin A tan 6+-cos A Theform ofthese equations shows that it is possible to satisfy the condition tanor-tan B for a compatible magnitude of the variable c/x, which dependsupon the geometrical characteristics defined above and upon theparametric angle These functions give the answer with high accuracy andfew computations. More spectacular functions, illustrated in FIG. 3 areobtained in expressing tan a and tan B, with X/R for the independentvariable. These functions show that the corresponding center ofcurvature denoted CR, (optimum), is located in respect to point C on theother side of the transversal diameter HH, normal to the radialdirection.

The cam 50 which has point C for both center of curvature andinstantaneous center of oscillation does not tend under the engagementprocess to attack from one end while leaving from another end, theactive surface 11 of the driving race. Because the equality of theangles of divergence, a=B=constant, is satisfied all over the activesurface 52 of the cam 50, this latter tends to penetrate uniformly by atranslation motion, through the driving surface 11 of the motor race 10and applies on a pressure which is therefore uniformly distributed.

For the associated upper primary cam and secondary cam 50, the locus ofthis privileged center CR, (optimum), expressed as a function of theparametric angle 5, is a line extended from the central point 0 in theleft direction, under the diameter I-II-I normal to the radial direction0C joining the 40 center 0 to the profile view C of the center ofpressure of the secondary upper cam 50. The fraction of locus comprisedin the interval 077i, (optimum) corresponds to the cams able toautomatically engage between their adjacent active surfaces. Therelative magnitude of this distance is is equal to the frictioncoefficient f of the contacting surfaces. 5 Consequently for everynature of surface this length is different but the point CR (optimum)defined the same boundary beyond which the corresponding cams require anexternal force to engage.

With the explanations given above, it is possible to see how under theseoperating conditions the clutchs components operate without deformationand therefore, without change of configuration. The passage between theengagement and disengagement phases results in a respective increase ordecrease of pressure between the contacting area and without relativemotion between the cams and their bearing surfaces. It is acharacteristic of this clutch that to allow the components a possibilityto move is a sufficient condition for their operating without performingthe smallest displacement.

The above properties result in the following facts:

A. The Induced Forces are always proportional to the magnitude of theinducing forces, a condition which satisfies the Stability Criterion ofthe torque and motion transmission.

B. The cams permanently operate under the same engaging angle, i.e. witha constant maximum efiiciency.

In FIG. 4 is illustrated an overrunning clutch where the internal race10 is the driving member, which is integral with the driving shaft 30,or fixed on by means ofa key 31. A series of secondary earns 40 with ashape similar to that of the primary earns 40 is distributed around withtheir head surfaces 52 all applied on the driving surface 11. Their basesurfaces 51 are permanently seated on the heads surface 42 of a secondseries of primary earns 40 the base surfaces 41 of which are permanentlyseated in coincidence on the bearing surfaces 21 of the driven race 20.All the contacting surfaces of the earns 40 and 50 and of the bearings20 are concaves. The bearing surfaces 21 are separated one from theother by the radial step 22 which is prolonged by the lip 23 radiallydirected towards the driving surface 11.

The instantaneous centers of oscillation and curvature of the cams andbearings surfaces are, in this concept, all located to the right side ofthe central axis of rotation O, and the locus, for each cam, of theCenter Optimum, CR, (optimum), is extended from the point 0 in the rightdirection, with a position about symmetrical of that shown for thecorresponding upper ca ms of the overrunning clutch of FIG. 1.

FIG. 5 illustrates the use of single cams 50 with the center ofcurvature and oscillation CR (optimum) corresponding to the angle ofdisengagement 5.

The driving member is a drum 10 rotating around a central axis of trace0. Each cam 50 is mounted articulated on an axle 57 which is supportedby a pair of flanges or collecting means 59 located one on each side ofthe cams 50. The flanges 59 are acting at once, as a guide whichmaintain the cams 50in alignment, as an actuator transmitting to thecams 50 an external tangential force Fe, and as a synchronizer whichtransmit to all the cams 50 a simultaneous angular displacement. Thecams 50 can then be used as brake shoes. The cams 50 are supported by afixed member, or fixed race 20 on which is seated their base surface 51.The head surface 52 of the earns 50 comprise a brake lining 81 whichallows a large friction coeffi cient, f, therefore a large angle 5 Somerolling device can be interposed between the bearing surfaces 21 and thecams base surface 51, for the sole purpose of reducing the magnitude ofthe angle of disengagement A recalling spring 60 maintain at rest therear side of the earns 50 applied on the front face of the radial step22. To drive the cams 50 in operation requires the application of atangential force F0 on the cams articulation 57, through an infinitelysmall angular displacement of the flanges-actuators 59.

The embodiment of FIG. 5 could also be a clutch by converting fixedmember 20 to a rotatable driven member.

While in accordance with the patent statutes only a certainrepresentative embodiment has been illustrated and described in detail,it is to be understood that the invention is not limited thereto orthereby, but that the inventive concept is defined in the appendedclaims.

What I claim is:

1. An overrunning clutch, comprising:

a first race formed for connection with a rotatable member,

having a central longitudinal axis, and defining a cylindrical activesurface with a continuous circumferential profile;

a second race coaxially mounted with the first race, integral with asecond member, having a series of excentric partial cylindrical surfaceseach with a circumferential arc profile constituting a series ofspirals, all developing their openings in the same direction, and withsuch surfaces constituting a series of bearing surfaces positionedfacing the active surface of the first race at such a distance apart toconstitute a series of excentric partial cylindrical primary annularspaces, the end of each of said primary annular spaces being separatedfrom the origin of the next by a radial step prolonged by a lip formedat the end of every primary annular space which is radially directedtoward the active surface of the first race;

a series of primary cams shaped as long curved wedges, one primary cambeing mounted inside each of the annular spaces with the thickened endof the cam substantially against the radial step of the space and thefirst side thereof seated in coincidence on the bearing surface of thesecond race;

a series of secondary cams shaped as long curved wedges,

one secondary cam being mounted inside each of the annular spaces withthe thickened end of the cam substantially against the radial step ofthe space, the first side of each secondary cam having the same profileand average excentricity as the second side of the primary cam, and thesecond side of each secondary cam having an active surface insubstantially adjacent concentric alignment with the active surface ofthe first race; and

means urging the thin end of each cam toward the rear side of the lip ofthe adjacent annular space,

2. A clutch according to claim 1 which includes key guides at the end ofeach cam to insure their alignment with respect to the races and eachother during rotative movement thereof.

3. A clutch according to claim 1 which includes spring means associatedwith each primary and secondary cam urging said cams toward their thinends thereby normally providing a wedged engaging relationship of thecams between the first race and the second race.

4. A clutch according to claim 3 where the numerical value of thetangent of the angle of disengagement of the primary cams to the secondrace is greater than the friction coefficient developed between suchsurfaces, and where the numerical value of the tangent of the angleofengagement of the primary cams to the secondary cams is not greaterthan the friction coefficient developed between such surfaces.

5. A clutch according to claim 1 where the average excentricity of eachprimary cam active surface is equal to the tangent of the angle formedby the radius of their profile and the radius of the driving surfaceprofile which meet each other at the middle length of the profile of thecams driving surface.

6. A clutch according to claim 5 where the sum of the base areas of allthe secondary cams is substantially of the same magnitude as the totalareas of the driving surfaces of the primary cams.

7. An overrunning clutch comprising a. A driving race formed forconnection with a motor for rotary, continuous or oscillating motion,having a central longitudinal axis, and defining a driving cylindricalactive surface with a continuous circumferential profile,

b. A driven race coaxially mounted with the driving race integral withthe driven member having a series of excentric partial cylindricalsurfaces each with a circumferential arc profile constituting a seriesof spirals, all developing their opening in the same direction with theexcentric partial cylindrical surfaces constituting a series of bearingsurfaces, positioned facing the driving surface of the driving race atsuch a distance apart to constitute a series of excentric partialcylindrical primary annular spaces with the end of each one of saidprimary annular spaces separated from the origin of the next by a radialstep prolonged by a lip formed at the end of every primary annular spacewhich is radially directed toward the driving surface, with the averageexcentricity of the profile of the primary annular space equal to thetangent of the angle formed by the radius of their profile and theradius of the driving surface profile, which meet each other at themiddle length of the profile of the primary annular space,

c. A series of primary cams mounted each one inside one of the excentricprimary partial annular spaces shaped as long curved wedges with theirbase surface permanently seated in coincidence on the bearing surface oftheir excentric annular space and having therefore the same profile andthe same average excentricity which is equal to the tangent of the angleof disengagement of said primary cams, for which the center of curvatureis also the instantaneous center of oscillation, the sum of the baseareas of all the primary cams having the same order of magnitude as thetotal area of the driven races bearing surfaces on which they areseated, said primary cams mechanically rotating with the driven race,spring means urging the front end of each primary cam toward the rearside of its own bearing's lip, the primary cams head surface facing theactive surface of the driving race at such a distance apart so as toconstitute a series of secondary excentric partial cylindrical annularspaces, the average excentricity of the primary cams head surfaceprofile equal to the tangent of the angle formed by the radius of theirprofile and the radius of the driving surface profile which meet eachother at the middle length of the profile of the cams head surface, and

d. A series of secondary cams mounted each one inside one of theexcentric secondary partial annular spaces, looking like long curvedwedges, with their base surface permanently seated in coincidence of thehead surface of one of the primary cams, having substantially the sameprofile and the same average excentricity equals to the tangent of theangle of engagement of said secondary cams, for which the center ofcurvature is also the instantaneous center of oscillation, the sum ofbase areas of the secondary cams being substantially the same as thetotal areas of the head surfaces of the primary cams, and the sum of thehead areas of all the secondary cams being substantially the same as thetotal area of the driving surface of the motor race.

8. A clutch according to claim 7 which includes means to protect thecams against the direct action of centrifugal force by utilizing afraction of the centrifugal force to tangentially energize the cams inthe positive direction, wherein the centers of curvature, for thebearing surface profiles and the cams base and head profiles are locatedtoward the general axis of rotation on a straight line which forms atthe point median of the head profile of the cam seated on the drivingsurface the selected angle of engagement or disengagement, with theradius of the driving surface of the driving race, and which includessmall pistons cooperating with the spring means to prevent directengagement of the spring means with the radial steps and lips.

9. An overrunning clutch comprising a first race formed for connectionwith a rotatable member having a central longitudinal axis and defininga cylindrical active surface with a continuous circumferential profile,a second race coaxially mounted with the first race and designed to beintegral with a second member, said second race having a series ofexcentric partial cylindrical surfaces each with a circumferential arcprofile constituting a series of spirals, all developing their openingin the same direction, and with such surfaces constituting a series ofbearing surfaces positioned facing the active surface of the first raceat such a distance apart to constitute a series of excentric partialcylindrical primary annular spaces, the end of each of said primaryannular spaces separated from the origin of the next by a radial stepprolonged by a lip formed at the end of every primary annular spacewhich is radially directed towards the active surface of the first race,a series of cam means shaped as long curved wedges mounted each oneinside one of the annular spaces with their thickened end substantiallyagainst the radial step of the space and the length thereof seated incoincidence on the bearing surface of such annular space, and eachhaving the same profile and the same average excentricity, said cammeans mechanically rotating with the second race, spring means urgingthe thin end of each cam means toward the rear side of the lip of theadjacent annular space, said cam means having active surfaces insubstantially adjacent concentric alignment and normally urged intoengagement with the active surface of the first race, and said cam meansbeing pivotally mounted independently of said first race at about thecentral point of their length upon an axis substantially parallel to thecentral longitudinal axis thereof, and means to selectively controlpivotal action of such cam means to control the engagement thereof withthe first race.

10. An all mechanical automatic overrunning clutch comprising:

a driving race coaxially mounted to a motor member rotating around amain central longitudinal axis, with said driving race comprising acylindrical active surface;

a driven race fixed to a receptor member coaxially mounted with respectto the driving race, with said driven race comprising a series ofpartial cylindrical excentric surfaces having an identicalcircumferential arc profile for constituting all together acircularseries of spirals developing their opening in the samedirection, with said partial cylindrical excentric surfaces constitutinga series of bearing surfaces facing in spaced relation the activecylindrical surface of said driving race for determining between theirown surface and said driving race surface a series of partial,excentric, cylindrical annular spaces, with both ends of each one ofsaid bearing surfaces of the driven race separated from the surfaces ofthe adjacent bearings, a pair of superposed primary and secondary cammeans substantially similarly shaped like long curved wedges mountedinside each one of said partial excentric cylindrical annular space,with the inner superposed contacting surfaces of said primary andsecondary cams means having an identical profile to allow them arelative free sliding motion, with each pair of primary and secondarycam means inserted like one unique cam inside their own annular spacewith the outer surface of said primary cam means permanently contactingthe bearing surface of the driven race and with the outer surface ofsaid secondary cam means permanently contacting the active surface ofthe driving race, with the absolute excentricity of the profile of saidprimary cam means greater than the absolute excentricity of the profileof said secondary cam means; means to limit the movement of each primarycam relative to the driven race in the direction of positive movement,said secondary cam being limited in its movement by the wedging actionbetween the primary cam and the driving race, means urging each saidprimary cam means positively in contacting engagement with the means tolimit, and means urging each secondary cam means in the positivedirection.

11. A clutch according to claim 10 where the means urging the primaryand secondary cam means are individual springs means with said springmeans received inside a cylindrical cavity formed inside said primaryand secondary cam means and mounted on some appropriate guides with oneend comprising a piston with a small part of which is coming out of thethicker end of the cam for taking support on the frontal face of therear separator of the annular spaces of said cam means.

12. A clutch according to claim 10 which includes key guides at bothends of each cam means to insure their alignment with respect to thesymmetrical plane of the races and with each other during rotativemovement thereof.

13. A clutch according to claim 10 where:

the maximum excentricity of the profile of the active surface of saidprimary cam means which is seated in coincidence on the driven racebearing passive surface, can be expressed by the tangent magnitude ofthe angle formed by the intersection of the radius of curvature of theirprofile with the radius of curvature of the profile of the activesurface of the driving race located at the middle length of itscorresponding secondary cam surface profile which permanently contactssaid driving race surface;

the minimum excentricity of the surface profile of said primary cammeans is equal to the maximum excentricity of the surface profile ofsaid secondary cam seated on it and can be expressed by the tangentmagnitude of the angle formed by the radius of curvature of the commonprofile of their coinciding surfaces with the radius of curvature of theprofile of the active surface of the driving race, located at the middlelength of its corresponding secondary cam surface profile whichpermanently contacts said driving race surface.

14. A clutch according to claim 13 where the magnitude of the tangent ofthe maximum eccentricity of the primary cam means is equal to thetangent of the disengagement angle and can be greater than the frictioncoefficient developed between the contacting surface, and where themagnitude of the tangent of the minimum excentricity of said primary cammeans is equal to the tangent of the engagement angle and can be smallerthan the friction coefficient developed between the contactin areas.

15. A c utch according to claim 10 where the sums of all the contactingareas between the active surfaces of the primary cam means and thecoinciding receptive bearing surfaces of the driven race, between boththe active surfaces of the secondary cams means and the coincidingreceptive surfaces of the primary cam means, and between the receptivesurface of the secondary cam means and the coinciding active surface ofthe driving race, are substantially of the same magnitude.

16. A nonautomatic wholly mechanical clutch comprising a driving racecoaxially mounted to a motor member rotating around a main centrallongitudinal axis, with said driving race comprising a cylindricalactive surface, a driven race fixed to a receptor member coaxiallymounted with respect to the driving race, with said driven racecomprising a series of partial cylindrical excentric surfaces having anidentical circumferential arc profile and constituting all together acircular series of spirals developing their opening in the samedirection, with said partial cylindrical excentric surfaces constitutinga series of bearing surfaces facing in spaced relation a part of theactive cylindrical surface of said driving race for determining betweentheir own surface and said driving race surface a series of partial,excentric cylindrical annular spaces, with both ends of each one of saidbearing surfaces of the driven race separated from the surfaces of theadjacent bearings, a pair of primary and secondary cams meanscooperating together like one unit to have only one same engaging anddisengaging angle the tangent of which is greater than the frictioncoefficient developed between the contacting areas so that said cammeans cannot operate by themselves, elastic means normally urging thereceptive surface of said cam means out of contact with the activesurface of the driving race and permanently urging the thicker end ofsaid cam means in the negative rotational direction, means to limit themovement of each primary cam relative to the driven race in thedirection of positive movement, means to provide an external tangentialforce which in first action overcomes the negative and permanent actionof said elastic means urging the thicker end of the cam means in thenegative direction in contacting engagement with the means to limit, andwhich in second action causes the cam means to run up on the driven racebearing surfaces to engage the receptive surfaces of the cam means withthe surface of the active driving and with said engaging actionvanishing with the withdrawal of the external force.

17. The nonautomatic mechanical clutch as described in claim 16 wheremeans are interposed between the gliding surfaces of the cam means andthe surface of the driven race to minimize the resistance to engagingand disengaging motion.

18. The nonautomatic mechanical clutch as described in claim 16 wheresaid driven race is mounted fixed so that said nonautomatic clutch actsas a brake with said collecting means permitting control by means of anexternal force the engagement of the cam means with the driving race.

H9. The nonautomatic mechanical clutch as described in claim 16 wheresaid cam means are pivotally mounted at a selected location of theirlength upon one axis substantially parallel to the central longitudinalaxis of the clutch, with all said axis for pivoting motion of the cammeans mounting on a collecting means, and where elastic means areprovided between said pivotal axis and the collecting means to allowsaid cam means to perform a double circumferential and radialdisplacement without constraint.

1. An overrunning clutch, comprising: a first race formed for connectionwith a rotatable member, having a central longitudinal axis, anddefining a cylindrical active surface with a continuous circumferentialprofile; a second race coaxially mounted with the first race, integralwith a second member, having a series of excentric partial cylindricalsurfaces each with a circumferential arc profile constituting a seriesof spirals, all developing their openings in the same direction, andwith such surfaces constituting a series of bearing surfaces positionedfacing the active surface of the first race at such a distance apart toconstitute a series of excentric partial cylindrical primary annularspaces, the end of each of said primary annular spaces being separatedfrom the origin of the next by a radial step prolonged by a lip formedat the end of every primary annular space which is radially directedtoward the active surface of the first race; a series of primary camsshaped as long curved wedges, one primary cam being mounted inside eachof the annular spaces with the thickened end of the cam substantiallyagainst the radial step of the space and the first side thereof seatedin coincidence on the bearing surface of the second race; a series ofsecondary cams shaped as long curved wedges, one secondary cam beingmounted inside each of the annular spaces with the thickened end of thecam substantially against the radial step of the space, the first sideof each secondary cam having the same profile and average excentricityas the second side of the primary cam, and the second side of eachsecondary cam having an active surface in substantially adjacentconcentric alignment with the active surface of the first race; andmeans urging the thin end of each cam toward the rear side of the lip ofthe adjacent annular space.
 2. A clutch according to claim 1 whichincludes key guides at the end of each cam to insure their alignmentwith rEspect to the races and each other during rotative movementthereof.
 3. A clutch according to claim 1 which includes spring meansassociated with each primary and secondary cam urging said cams towardtheir thin ends thereby normally providing a wedged engagingrelationship of the cams between the first race and the second race. 4.A clutch according to claim 3 where the numerical value of the tangentof the angle of disengagement of the primary cams to the second race isgreater than the friction coefficient developed between such surfaces,and where the numerical value of the tangent of the angle of engagementof the primary cams to the secondary cams is not greater than thefriction coefficient developed between such surfaces.
 5. A clutchaccording to claim 1 where the average excentricity of each primary camactive surface is equal to the tangent of the angle formed by the radiusof their profile and the radius of the driving surface profile whichmeet each other at the middle length of the profile of the cams drivingsurface.
 6. A clutch according to claim 5 where the sum of the baseareas of all the secondary cams is substantially of the same magnitudeas the total areas of the driving surfaces of the primary cams.
 7. Anoverrunning clutch comprising a. A driving race formed for connectionwith a motor for rotary, continuous or oscillating motion, having acentral longitudinal axis, and defining a driving cylindrical activesurface with a continuous circumferential profile, b. A driven racecoaxially mounted with the driving race integral with the driven memberhaving a series of excentric partial cylindrical surfaces each with acircumferential arc profile constituting a series of spirals, alldeveloping their opening in the same direction with the excentricpartial cylindrical surfaces constituting a series of bearing surfaces,positioned facing the driving surface of the driving race at such adistance apart to constitute a series of excentric partial cylindricalprimary annular spaces with the end of each one of said primary annularspaces separated from the origin of the next by a radial step prolongedby a lip formed at the end of every primary annular space which isradially directed toward the driving surface, with the averageexcentricity of the profile of the primary annular space equal to thetangent of the angle formed by the radius of their profile and theradius of the driving surface profile, which meet each other at themiddle length of the profile of the primary annular space, c. A seriesof primary cams mounted each one inside one of the excentric primarypartial annular spaces shaped as long curved wedges with their basesurface permanently seated in coincidence on the bearing surface oftheir excentric annular space and having therefore the same profile andthe same average excentricity which is equal to the tangent of the angleof disengagement of said primary cams, for which the center of curvatureis also the instantaneous center of oscillation, the sum of the baseareas of all the primary cams having the same order of magnitude as thetotal area of the driven races bearing surfaces on which they areseated, said primary cams mechanically rotating with the driven race,spring means urging the front end of each primary cam toward the rearside of its own bearing''s lip, the primary cams'' head surface facingthe active surface of the driving race at such a distance apart so as toconstitute a series of secondary excentric partial cylindrical annularspaces, the average excentricity of the primary cams'' head surfaceprofile equal to the tangent of the angle formed by the radius of theirprofile and the radius of the driving surface profile which meet eachother at the middle length of the profile of the cams'' head surface,and d. A series of secondary cams mounted each one inside one of theexcentric secondary partial annular spaces, looking like long curvedwedges, with their base surface permAnently seated in coincidence of thehead surface of one of the primary cams, having substantially the sameprofile and the same average excentricity equals to the tangent of theangle of engagement of said secondary cams, for which the center ofcurvature is also the instantaneous center of oscillation, the sum ofbase areas of the secondary cams being substantially the same as thetotal areas of the head surfaces of the primary cams, and the sum of thehead areas of all the secondary cams being substantially the same as thetotal area of the driving surface of the motor race.
 8. A clutchaccording to claim 7 which includes means to protect the cams againstthe direct action of centrifugal force by utilizing a fraction of thecentrifugal force to tangentially energize the cams in the positivedirection, wherein the centers of curvature, for the bearing surfaceprofiles and the cams'' base and head profiles are located toward thegeneral axis of rotation on a straight line which forms at the pointmedian of the head profile of the cam seated on the driving surface theselected angle of engagement or disengagement, with the radius of thedriving surface of the driving race, and which includes small pistonscooperating with the spring means to prevent direct engagement of thespring means with the radial steps and lips.
 9. An overrunning clutchcomprising a first race formed for connection with a rotatable memberhaving a central longitudinal axis and defining a cylindrical activesurface with a continuous circumferential profile, a second racecoaxially mounted with the first race and designed to be integral with asecond member, said second race having a series of excentric partialcylindrical surfaces each with a circumferential arc profileconstituting a series of spirals, all developing their opening in thesame direction, and with such surfaces constituting a series of bearingsurfaces positioned facing the active surface of the first race at sucha distance apart to constitute a series of excentric partial cylindricalprimary annular spaces, the end of each of said primary annular spacesseparated from the origin of the next by a radial step prolonged by alip formed at the end of every primary annular space which is radiallydirected towards the active surface of the first race, a series of cammeans shaped as long curved wedges mounted each one inside one of theannular spaces with their thickened end substantially against the radialstep of the space and the length thereof seated in coincidence on thebearing surface of such annular space, and each having the same profileand the same average excentricity, said cam means mechanically rotatingwith the second race, spring means urging the thin end of each cam meanstoward the rear side of the lip of the adjacent annular space, said cammeans having active surfaces in substantially adjacent concentricalignment and normally urged into engagement with the active surface ofthe first race, and said cam means being pivotally mounted independentlyof said first race at about the central point of their length upon anaxis substantially parallel to the central longitudinal axis thereof,and means to selectively control pivotal action of such cam means tocontrol the engagement thereof with the first race.
 10. An allmechanical automatic overrunning clutch comprising: a driving racecoaxially mounted to a motor member rotating around a main centrallongitudinal axis, with said driving race comprising a cylindricalactive surface; a driven race fixed to a receptor member coaxiallymounted with respect to the driving race, with said driven racecomprising a series of partial cylindrical excentric surfaces having anidentical circumferential arc profile for constituting all together acircular series of spirals developing their opening in the samedirection, with said partial cylindrical excentric surfaces constitutinga series of bearing surfaces facing in spaced relation the activecylindrical surface of Said driving race for determining between theirown surface and said driving race surface a series of partial,excentric, cylindrical annular spaces, with both ends of each one ofsaid bearing surfaces of the driven race separated from the surfaces ofthe adjacent bearings, a pair of superposed primary and secondary cammeans substantially similarly shaped like long curved wedges mountedinside each one of said partial excentric cylindrical annular space,with the inner superposed contacting surfaces of said primary andsecondary cams means having an identical profile to allow them arelative free sliding motion, with each pair of primary and secondarycam means inserted like one unique cam inside their own annular spacewith the outer surface of said primary cam means permanently contactingthe bearing surface of the driven race and with the outer surface ofsaid secondary cam means permanently contacting the active surface ofthe driving race, with the absolute excentricity of the profile of saidprimary cam means greater than the absolute excentricity of the profileof said secondary cam means; means to limit the movement of each primarycam relative to the driven race in the direction of positive movement,said secondary cam being limited in its movement by the wedging actionbetween the primary cam and the driving race, means urging each saidprimary cam means positively in contacting engagement with the means tolimit, and means urging each secondary cam means in the positivedirection.
 11. A clutch according to claim 10 where the means urging theprimary and secondary cam means are individual springs means with saidspring means received inside a cylindrical cavity formed inside saidprimary and secondary cam means and mounted on some appropriate guideswith one end comprising a piston with a small part of which is comingout of the thicker end of the cam for taking support on the frontal faceof the rear separator of the annular spaces of said cam means.
 12. Aclutch according to claim 10 which includes key guides at both ends ofeach cam means to insure their alignment with respect to the symmetricalplane of the races and with each other during rotative movement thereof.13. A clutch according to claim 10 where: the maximum excentricity ofthe profile of the active surface of said primary cam means which isseated in coincidence on the driven race bearing passive surface, can beexpressed by the tangent magnitude of the angle formed by theintersection of the radius of curvature of their profile with the radiusof curvature of the profile of the active surface of the driving racelocated at the middle length of its corresponding secondary cam surfaceprofile which permanently contacts said driving race surface; theminimum excentricity of the surface profile of said primary cam means isequal to the maximum excentricity of the surface profile of saidsecondary cam seated on it and can be expressed by the tangent magnitudeof the angle formed by the radius of curvature of the common profile oftheir coinciding surfaces with the radius of curvature of the profile ofthe active surface of the driving race, located at the middle length ofits corresponding secondary cam surface profile which permanentlycontacts said driving race surface.
 14. A clutch according to claim 13where the magnitude of the tangent of the maximum eccentricity of theprimary cam means is equal to the tangent of the disengagement angle andcan be greater than the friction coefficient developed between thecontacting surface, and where the magnitude of the tangent of theminimum excentricity of said primary cam means is equal to the tangentof the engagement angle and can be smaller than the friction coefficientdeveloped between the contacting areas.
 15. A clutch according to claim10 where the sums of all the contacting areas between the activesurfaces of the primary cam means and the coinciding receptive bearingsurfaces of the driven race, between both the active surFaces of thesecondary cams means and the coinciding receptive surfaces of theprimary cam means, and between the receptive surface of the secondarycam means and the coinciding active surface of the driving race, aresubstantially of the same magnitude.
 16. A nonautomatic whollymechanical clutch comprising a driving race coaxially mounted to a motormember rotating around a main central longitudinal axis, with saiddriving race comprising a cylindrical active surface, a driven racefixed to a receptor member coaxially mounted with respect to the drivingrace, with said driven race comprising a series of partial cylindricalexcentric surfaces having an identical circumferential arc profile andconstituting all together a circular series of spirals developing theiropening in the same direction, with said partial cylindrical excentricsurfaces constituting a series of bearing surfaces facing in spacedrelation a part of the active cylindrical surface of said driving racefor determining between their own surface and said driving race surfacea series of partial, excentric cylindrical annular spaces, with bothends of each one of said bearing surfaces of the driven race separatedfrom the surfaces of the adjacent bearings, a pair of primary andsecondary cams means cooperating together like one unit to have only onesame engaging and disengaging angle the tangent of which is greater thanthe friction coefficient developed between the contacting areas so thatsaid cam means cannot operate by themselves, elastic means normallyurging the receptive surface of said cam means out of contact with theactive surface of the driving race and permanently urging the thickerend of said cam means in the negative rotational direction, means tolimit the movement of each primary cam relative to the driven race inthe direction of positive movement, means to provide an externaltangential force which in first action overcomes the negative andpermanent action of said elastic means urging the thicker end of the cammeans in the negative direction in contacting engagement with the meansto limit, and which in second action causes the cam means to run up onthe driven race bearing surfaces to engage the receptive surfaces of thecam means with the surface of the active driving and with said engagingaction vanishing with the withdrawal of the external force.
 17. Thenonautomatic mechanical clutch as described in claim 16 where means areinterposed between the gliding surfaces of the cam means and the surfaceof the driven race to minimize the resistance to engaging anddisengaging motion.
 18. The nonautomatic mechanical clutch as describedin claim 16 where said driven race is mounted fixed so that saidnonautomatic clutch acts as a brake with said collecting meanspermitting control by means of an external force the engagement of thecam means with the driving race.
 19. The nonautomatic mechanical clutchas described in claim 16 where said cam means are pivotally mounted at aselected location of their length upon one axis substantially parallelto the central longitudinal axis of the clutch, with all said axis forpivoting motion of the cam means mounting on a collecting means, andwhere elastic means are provided between said pivotal axis and thecollecting means to allow said cam means to perform a doublecircumferential and radial displacement without constraint.